Message Path Delays in Packet-Switching Communication Networks

A communication path (in isolation) in a packet-switching store-and-forward communication network, such as a computer or satellite-communication network, is considered. Messages are assumed to arrive according to a Poisson stream, and messagelengths are considered to be random variables governed by an arbitrary distribution. Message lengths are divided into fixed-length packets which are sent independently over the -channel communication path in a store-and-forward manner, and are reassembled at the destination terminal. Expressions for the distributions of the message waiting and delay times over the path are derived. Also, we obtain the limiting average message waiting times and required buffer sizes at the individual channels. The overall message waiting time is observed to depend only on the minimal channel capacity. The case of exponentially distributed message lengths serves as an illustrating example.